9. Rivers#

Related CPP options:


Activate point sources (rivers)


use analytical vertical profiles for point sources
(set in set_global_definitions.h)


Read variable river transports in netcdf file


Read variable river concentration in netcdf file

ANA_PSOURCE gives the vertical distribution of point source outflow. The default shape is an exponential vertical distribution. The vertical shape can be customized in subroutine ana_psource in analytical.F

An example of runoff file is given below

netcdf croco_runoff {
qbar_time = 28193 ;
n_qbar = 9 ;
runoffname_StrLen = 30 ;
two = 2 ;
temp_src_time = 10690 ;
salt_src_time = 10690 ;
double qbar_time(qbar_time) ;
  qbar_time:long_name = "runoff time" ;
  qbar_time:units = "days" ;
  qbar_time:cycle_length = 0. ;
  qbar_time:long_units = "days since 1900-01-01" ;
char runoff_name(n_qbar, runoffname_StrLen) ;
  runoff_name:long_name = "runoff name" ;
double runoff_position(n_qbar, two) ;
  runoff_position:long_name = "position of the runoff (by line) in the CROCO grid" ;
double runoff_direction(n_qbar, two) ;
  runoff_direction:long_name = "direction/sense of the runoff (by line) in the CROCO grid" ;
double Qbar(n_qbar, qbar_time) ;
  Qbar:long_name = "runoff discharge" ;
  Qbar:units = "m3.s-1" ;
double temp_src_time(temp_src_time) ;
  temp_src_time:cycle_length = 0. ;
  temp_src_time:long_units = "days since 1900-01-01" ;
double salt_src_time(salt_src_time) ;
  salt_src_time:cycle_length = 0. ;
  salt_src_time:long_units = "days since 1900-01-01" ;
double temp_src(n_qbar, temp_src_time) ;
  temp_src:long_name = "runoff temperature" ;
  temp_src:units = "Degrees Celcius" ;
double salt_src(n_qbar, temp_src_time) ;
  salt_src:long_name = "runoff salinity" ;
  salt_src:units = "psu" ;

When using PSOURCE, Isrc and Jsrc refer to the i,j index of the u-face or v-face the flow crosses - NOT the i,j index of the rho cell it flows into. The i,j values must follow ROMS Fortran numbering convention for the appropriate u-point or v-point on the ROMS staggered grid.

This numbering convention is shown in the figure below (Courtesy of ROMS-RUTGERS team) for flow crossing a u-face into a cell from either the left or the right. This makes it more obvious why the index of the u-face must be specified, because to give the i,j indices of the receiving rho-cell would be ambiguous.

The u-face or v-face should be a land/sea mask boundary (i.e. a coastline). If the cell face is placed wholly in the land you get nothing because there is no wet cell for the flow to enter. If the face is in the middle of open water you have a situation where the flow at that cell face computed by the advection algorithm is ‘REPLACED, not augmented, by the source.

It is very easy to misconfigure source/sink locations so caution and careful checking is required.